We have 26 letters and 5 digits 0, 2, 4, 6, and 8 in our possession. Any of 26 letters in the 1-st position; any of 25 remaining letters in the 2-nd position; any of 24 --------- " ----------- 3-rd position; any of 23 --------- " ----------- 4-th position; any of 5 digits in the 5-nd position; any of 4 remaining digits in the 6-nd position. In all, 26*25*24*23*5*4 = 7176000 different codes are possible.